Numbers 19:9-10

9Then someone who is ceremonially clean will gather up the ashes of the heifer and deposit them in a purified place outside the camp. They will be kept there for the community of Israel to use in the water for the purification ceremony. This ceremony is performed for the removal of sin.

10The man who gathers up the ashes of the heifer must also wash his clothes, and he will remain ceremonially unclean until evening. This is a permanent law for the people of Israel and any foreigners who live among them.